Since the output target here is the temporal span of the spoken answer, following the evaluation metrics, previously proposed [1]}, [2]}, we adopted the Frame-level F1 score (FF1) and Audio Overlapping Score (AOS) to evaluate the performance based on the predicted time intervals:
<TABLE>\(P &= \frac{X \cap Y}{X} & R &= \frac{X \cap Y}{Y} \\FF1 &= \frac{2\times P \times R}{P+R}\times 100\% & AOS &= \frac{X \cap Y}{X \cup Y}\times 100\%\) 
